Pliers



Patented May 25, 1926.

:UNITEDYI'STIATES" PATENT, OFFICE;

HENRY c. nu 1301s, or STRATFORD,-GONNECTICUT,,ASSIG1\IOR TO AMERICAN CHAIN COMPANY, mo, 4 CORPORATION on NEW $03K;

PLIERS.

Application filed September 12, 1924. ,iserial No. 737,234.

This invention relates to pliers, and is of particular utility when embodied in the construction ofa tool of this class for opening and closing hooks of cross-chains for automobile tires, in the operation of applying or removing such tire chains, although I contemplate the utilization of my improvements in any field of operation for which they may be adapted by their nature. 7 v 7 An object of the invention is to provide pliers having jaws compounded with actuating handles in such fashion that the leverage resulting from spreading the handles far apart produces a wide openingmovement of the jaws with but little exertion, while the leverage resulting from closing movement of the handles operates to cause a rapid initial approach of thejaws toward each other with but littlepressure applied to the handles, and then the motion of the jaws thus constituted. can be manufactured at, a.

very advantageous cost from only three sets of blanks. i I x p .7

Another object of the invention is to connect the handles with the compounding extensions permanently and rigidly so that each extensions-handle may be regarded as a unitary member in the completed tool,-

which is therefore composed simply of two component parts are arranged compactly in contiguous plane-s so that one jaw and one extension-member operate in one plane, and the other jaw and extension-member operate in a plane immediately adjacent thereto, the jaws and extensions being formed with broad bearing surfaces to afford an unusual. degree of rigidity in thesystem of levers constituted thereby.

Referring to the drawings Figure 1 is a side elevation of a pair of pliers inv the construction of which the in- Wja w pivot 5 in the arc of 'a'circlei V aws and two extension-handles,and these vention is embodied, shown in closed position. o j,

' Figure 2 is a front elevation thereof.

Figure 3 is a side elevation of the pliers opened to a distance of'about midway of their throw. i In the illustrated embodiment the reference characters 1 and 2 designate respectively the jaw members of a pair of pliers, having jaw portions 3 which may be of any suitable form, according to the work to be performed, and which are shown as pointed, for convenient engagement with the hooks of cross-chains for example, and whichmay alsoconveniently embody wire cutting portions 40f well known function and arrangen'1ent,'the jaws rotating in crossed relation about a fixed pivot 5. o a

The shanks 6 of these jaws are provided respectively at about their middle, with pivots 7, each pivot constituting a fulcrum for. a lever of the second order which is formed in each 111813211106 by an extension member 8 ates in ,a'slot 10 formed in the body portion 11 of the other extension-member 8, these extension-members having preferably each a suitablehandlel2 riveted theretoat 13. i Y The jaw members 6 constitute a virtually complete pair of crossed pliers in themselves,

and the extension-members 8 cross each other in operation, somewhat as the jaws are cross ed, with this important novelarrangement,

viz, that while the pivotal connection 5 of the jaws with each other is fixed, in the sys-.

item of levers, the pivot connections 7 between the jaw-shanks and the handle extensions respectivelyare separated fromeach other, eachsuoh pivot constituting a floatmg fulcrum having amovement around the So also, the pin 9 at the outerjend of eachg j aw-shank 1s fixed relatively to its supp'orting shank, and describesian are upon a larger radius from the fixed jaw pivot, so

that the ratio between theilever arms constituted respectively bythe portions of the shanks 6 b'etw'een the pivots, 5 and 7 and bepivot- 5 and pins 9 respectively connectedtherewith, and in the outer end of each jaw-shank is fixed a pin' 9 which operslots being of a curved contour, designed to produce the maximum opening movement of the jaw shanks and jaws during the initial separation of the handles, decreasing as the pins travel toward the outer ends of the slots, and also designed' to afford the maximum development of closing pressure as the pins travel toward the inner ends of the slots, this combination of movement and pressure afiording precisely the effect which most readily opens and closes cross cha-in hooks.

In Figure l the pliers are shown as closed, with jaw points 3 overlapping and the pins 9.'- situated at the inner ends of the slots 10', the floating pivots 7 being in substantially axial alignment with each other, and the handles 12' are close enough together for the operator to grasp them bothin one hand, exerting conveniently a powerful pressure, owing to the proximity of each leverage pin 9 to the fulcrum pivot 7, having regard to each handle-extension in its capacity of a lever of the second order.

Figure 2 shows the arrangement of the component parts of the pliers compactly in adjacent planes, the extensions 11 being respectively oiiset at 14 so that one jaw and one extension lie in one plane, while the other jaw and other etension lie in another adjacent plane, the broad contiguous bearing surfaces affording a degree of rigidity which adds to the power, reliability, and durabilty of the pliers, and is especially advantageous in operating with the cutters 4t. 7

Each shank 6 is preferably provided with a short arm 15, offset to embrace the end 8 of the extension 11 connected therewith, so that the pivots 7 will be supported in suitable position to slide over each other and over the adjacent portion ofthe opposite lever 8, in the operation oiopening the pliers to, and beyond the position illustrated in Figure 3.

Having thus described my invention, I ci aim r 1. Pliers of the class described, comprising a pair of jaws having shanks assembled in crossed relation upon a main fixed pivot, and apair of extension-members connected in crossed relation to pivots upon said jaw- -shanks, said pivots having a floating relationship to each other, and each oii' said extension-members having a body slot in which is fitted to slide operatively a pin set in the free end of the jaw-shank opposite to the shank connected to said extensionmember, and each of said jaw-shank pivot-s being fixed to a portion of its supporting jaw-shank at a point between said main fixed pivot and the pin in the free end of said shank.

2. Pliers of the class described, comprising a single pair of working jaws having integral shanks assembled in crossed relation upon a fixed pivot, and a pair of extensionmembers of which one is connected to a fixed pivot upon the middle portion of one of the jaw-shanks, and the other is connected to a similar pivot upon the middle portion oi the other jaw-shank, and said extensionmembers having each a body slot in which is fitted to slide operatively a pin set in the free end of the jaw-shank opposite to the shank connected to said extension-member.

3. Pliers of the class described, comprising a pair of a-ws having shanks assembled in crossed relation upon a fixed pivot, and a pair of extensiouhandlesoi which one connected to a pivot upon the middle portion of one of the jaw-shanks, and the other is connected to a similar pivot upon the middle portion of the other jaw-shank, said pivots having a floating relationship and each being mounted in an offset short arm of its jaw-shank, so that each jaw and an opposed handle-extension lie in one and the same plane, and the other jaw and opposed handle-extensionlie in another, parallel plane, closely contiguous to each other, said handle-extensions having each a body slot in which is fitted to slide operatively a pin set in the free end of the jaw-shank opposite to the shank connected to said handle-extension by its floating pivot.

4.. Pliers of the class described,.comprising a pair of symmetrically formed jaws having shanks assembled in crossed relation upon a fixed pivot, and a pair of symmetrically formed extension-members of which one is connected to a pivot upon the middle portion of one of the jaw-shanks, and the other is connected to a similar pivot upon the middle portion of the other jaw-shank, said pivots having a floating relationship and each being mounted in an offset short arm of its jaw-shank, and said parts being otherwise fiat, so that each jaw and an opposed extension-member can lie in one and the same plane, and the other jaw and opposed extension-member will lie in another, parallel plane, closely contiguous to each other, said extension-members having respectively body slots in which are fitted to slide operatively' pins set in the free ends'of said jawshanks, and said extension-members having also separately formed handles U-shapcd in, cross-section, embracing said extensions and rigidly connected thereto.

5. Pliers of the class described, comprising a pair of symmetrically formed jaws assembled in crossed. relation upon a fixed pivot, and a pair of symmetrically formed, oitset extension-handles cross-connected to pivots carried by said jaws and having a floating relationship, and said extensions having respectively body slots in which are fitted to slide operatively pins set in the;

free ends of said jaws, said slots heing curved to produce a leverage designed to cause rapid openlng and closlng movements of said jaws upon operation of said extension-handles, and also to produce a powerful pressure between said jaws when approaching final closure, with the exertion of but little manual pressure upon said handles.

6. Pliers of the class described, comprising a pair of symmetrically formed jaws assembled in crossed-relation upon a fixed pivot, and a pair of symmetrically formed, offset extension-handles cross-connected to pivots carried by saidjaws and having a floating relationship, each of said pivots being mounted in an offset short arm of its jaw, so that each jaw and an opposed ex tension-handle lie in one and the same plane, and the other jaw and opposed extension:

handle lie in another, contiguous, plane, said handle-extensions having respectively body slots in which are fitted to slide operatively pins set in the free ends of said jaws.

7. Pliers of the class described, comprising a pair of symmetrically formed jaws assembled 1n crossed relation upon a fixed pivot,

. and a pair of symmetrically formed, extension-members cross-connected to pivots carried by said jaws and having a floating relationship, each of said pivots being mounted in an olfsetshort arm of its jaw, so that each jaw and an opposed extension-member lie in one and the same plane, and the other jaw and opposed extension-member lie in another, contiguous, plane, said extensionmembers having respectively body slots in which are fitted to slide operatively pins set in the free ends of said jaws, said body slots being curved to produce a leverage designed to cause'rapid opening and closing move ments of said jaws upon operation of said extension-members, and also to produce a powerful pressure between said jaws when approaching final closure, with the exertion of but little manual pressure upon said extension-members, said extension-members being offset respectively and provided with rounded grips or handles lying in the same plane.

v In testimony whereof, I have signed this specification.

.. HENRY o. DU BOIS. 

